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Article
EFFECT OF DIFFERENT TYPES OF LIGHTWEIGHT AGGREGATE ON STRENGTH AND MODULUS OF ELASTICITY OF CELLULAR CONCRETE

Authors: Suhad Mohammed Abd --- Dunay Khalil Ismail
Journal: Journal of Engineering and Sustainable Development مجلة الهندسة والتنمية المستدامة ISSN: 25200917 Year: 2019 Volume: 23 Issue: 5 Pages: 193-206
Publisher: Al-Mustansyriah University الجامعة المستنصرية

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Abstract

The objective of this study is to improve properties of structural foamed concretes by adding fine and coarse lightweight aggregate. The materials that used in this study were fly ash as fine material and various type of lightweight aggregate (Leca, porcelanite). The mechanical properties included fresh and hardened density, compressive strength and elasticity modulus were tested in this study. The results show increases in compressive strength and modulus of elasticity by increasing the percentage of fine aggregate (fly ash).The optimum percent is 50% for fine aggregate (fly ash).The compressive strength decreases with increasing the percentage of lightweight coarse aggregate .The modules of elasticity increases by increasing the replacement percentage of fly ash . The addition of lightweight coarse and fine aggregate affect on the percentage of foam need be added to the mix for the desired density. Type of aggregate have significant effect on compressive strength and modulus of elasticity for foamed concrete. Flyash increase in compressive strength about (39%). Light weight aggregate decrease in compressive strength about (2-50) %. Flyash increase in modulus of elasticity about (10-56)% and light weight aggregate increase in modulus of elasticity about (1-20)%. Fly ash and lightweight aggregate (Leca and Porcelanite) improved the properties of foamed concrete.


Article
Analysing Some Mechanical Properties of Cinnamon Powder Reinforced with Polymeric Materials Used in Dental Application

Authors: Ahamed M. AlGhabban --- Reem A. Mohammed --- Jumaah R. Mahmood
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2019 Volume: 37 Issue: 3 Part (A) Engineering Pages: 96-105
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

Abstract- In the dentures industry, materials must be chosen to have goodmechanical properties in order to resist the conditions that may occur in themouth. A study was conducted to assess tensile strength, elasticity coefficient,elongation, flexural strength, flexural modulus with impact properties of polymethyl methacrylate resin as matrix strengthened with cinnamon powder andalso analysing these mechanical properties by using (OriginLab) softwareprogram. The samples of Poly Methyl methacrylate bio composites whichcontaining 2%, 4%, 6%, and 8% weight fractions of cinnamon powder and anunfilled as control sample were fabricated using “hand lay up” method. Theresults indicate that the addition of 8% weight fraction cinnamon powder intoPoly Methyl methacrylate resin improved of ultimate tensile strength, moduluselasticity ,flexural strength, flexural modulus (62 MPa, 3.7 GPa, 96 MPa, 6.4GPa) respectively, compared with the values of pure Poly Methyl methacrylate(51 MPa, 1.5 GPa, 78MPa, 2.0 GPa) respectively. Also can be noted that theelongation at break values decreases with an increase in weight fractions offiller, where the sample (Poly Methyl methacrylate +2% cinnamon) has the bestvalue for elongation compared with samples reinforced (4%, 6% and 8% wt).The impact strength results observe the maximum value was present in thesample (Poly Methyl methacrylate+6% cinnamon). From the results,descriptive, One Way ANOVA statistical analysis and means comparison byused (Scheffe test and Tukey test) for all mechanical properties indicated, turnsout if Sig equals 1 shows that the variance in mean is significant at the level of0.05, whereas Sig is 0 designates that the mean variance is not significant at thelevel 0.05.


Article
Investigation the Variationof Bulk Modulus of Elasticity on The Performance of Conventional Electrohydraulic System

Authors: Walaa Mousa Hashim --- HudaAkram Al-Salihi --- Aws Falah Hassan
Journal: Journal of University of Babylon مجلة جامعة بابل ISSN: 19920652 23128135 Year: 2019 Volume: 27 Issue: 3 Pages: 170-181
Publisher: Babylon University جامعة بابل

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Abstract

Basically, all hydraulic performance systems are extremely reliant on the rising of theoil temperature, due to an increase in the pressure,decrease lubricate moving parts, increases leakage and dissipate heat. This could lead to the variation in bulk modulus of elasticity for different working cnditions,which could be affected in the performance of the system. Accordingly, an attempt was made to examine the effect of the bulk modules of elasticity on the accurate position. Six pressure supplierswere critically used (20, 30, 40, 50, 60 and 70) bar at five oil temperatures (25, 40, 50, 60 and 70) °C. Experimental results showed that the maximum variation percentage in the actuator displacement at the same load occurred at 70 °Coil temperature and therewere4.252%, 7.25% , 9.154% , 9.253%, 8,727%, 15.476 and 19.23% in 20 , 30, 40, 50, 60 and 70 bar pressure supply, respectively.

بصورة عامة ان جميعأنظمةالأداءالهيدروليكية تتاثربشكلكبير من ارتفاعدرجةحرارةالزيت المستخدم وذلكبسببزيادةالضغط وتزداد قيمتها مع ازدياد الضغوط المستخدمة،أن هذا الارتفاعيؤديإلىالتغيير في قيمة معاملالمرونة الحجمي للزيت المستخدم وبالتالي تقليل فاعلية الزيت في تزييت الأجزاءالمتحركة للمنظومة وزيادةمعدل نضوح الزيتوتبديدالحرارة من المنظومة والذي ينعكس سلبا على أداءالنظام. وفقًالذلك،في هذا البحث دراسة عمليةلتأثيرتغير قيمة معامل المرونة الحجمي علىالموقعالدقيق للمشغلات الهيدروليكية. تماستخدامستةقيمللضغوط المجهزة للمنظومة (20 ، 30 ، 40 ، 50 ، 60 و 70) باروعند خمس درجات حرارة للزيت (25 ، 40 ، 50 ، 60 و 70) درجةمئوية. أظهرتالنتائجالتجريبيةأنالحدالأقصىلنسبةالتغيرفيإزاحةالمشغل الهيدروليكيمابين الموقع المطلوب الحقيقي والعملي ولنفس الحملعنددرجةحرارة 70 درجةمئويةوهي4.252٪ ، 7.25٪ ، 9.154٪ ، 9.253٪ ، 8،727٪ ، 15.476 و 19.23٪ وللضغط المجهز 20 ، 30, ، 40 ، 50 ، 60 و 70 بارعلىالتوالي.


Article
Prospect of Using Locally DolomiteStone to Produce High Performance Concrete Pavement

Author: Fatimah Fahem Al-khafaji
Journal: Journal of University of Babylon مجلة جامعة بابل ISSN: 19920652 23128135 Year: 2019 Volume: 27 Issue: 3 Pages: 92-98
Publisher: Babylon University جامعة بابل

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Abstract

The fundamental objective of this research is to examine the manufacture of concrete pavement with a high performance by utilizing Samawa dolomitestone as a partial substitution to coarse aggregate (gravel). In this study, five mixes of concrete pavement were made containing Samwah stone as a coarse aggregate with the replacement percentage of (0%, 10%, 20%, 30% & 40%) from gravel at level of strength type C30 (the requirement of concrete pavement). Fresh concrete mixes were subjected to slumptest.Compressive strength, flexural strength, static modulus of elasticity was investigated for hardened concrete mixes at age of 28 days. Test results revealed that the inclusion of locally dolomite stone as a replacement to gravel in produced concrete pavement improves the hardened propertiesespecially for flexural strength without any significant effect on workability requirement except at replacement percentage (40% of coarse aggregate). The best performance of produced concrete pavement was adopted with replacement percentage (30%) from gravel by using locally dolomite stone.

أن الهدف الرئيسي من هذا البحث هو اختبار إنتاج خرسانة تبليط عالية الأداء من خلال استخدام حجارة الدولومايت من السماوة كبديل جزئي عن الركام الخشن (الحصى)في هذا العمل تم عمل خمس خلطات للتبليط الخرساني يحتوي على حجارة الدولومايت كركام خشن وبنسبه استبدال (0، 10، 20، 30، 40) % من الحصى ولمستوى مقاومه 30C والتي تمثل متطلبات خرسانة التبليط.تم أداء فحص الهطول للخرسانة الطرية وفحوصات مقاومة الانضغاط والانثناء ومعامل المرونة واختبارها للخرسانة الصلدة ولعمر 28 يوم.أظهرت النتائج أن تضمين حجارة الدولومايت من السماوة للركام الخشن في خرسانة التبليط تطورا واضحا في الخواص الصلبة وخاصه مقاومة الانثناء وبدون تأثير واضح على قابلية التشغيل عدا نسبه الاستبدال 40%.إن أفضل أداء لخرسانه التبليط المنتجة تحققت بنسبه استبدال 30%من الحصى وباستخدام تلك الحجارة المحلية (حجارة السماوة الدولومايت).

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